Control mechanism for the yarn carrier stops of a flat knitting machine



Jan. 23, 1968 E. KRAUSE CONTROL MECHANISM FOR THE YARN CARRIER STOPS OF A FLAT KNITTING MACHINE 5 Sheets-Sheet 1 Filed March 17, 1965 IN VENTOR Ema KHZ use Jan. 23, 1958 E. KRAUSE 3,354,793

CONTROL MECHANISM FOR THE YARN CARRIER STOPS OF A FLAT KNITTING MACHINE Filed March 17, 1965 5 Sheets-Sheet WVENTOR m En'ch Krcwse Ltti 8 @mw mgr BMW Jan. 23, 1968 E KRAUSE 3,364,703

CONTROL MECHANISM FOR THE YARN CARRIER STOPS OF A FLAT KNITTING MACHINE Filed March 17, 1965 Y 5 Sheets-Sheet 5 Erich Kraasa mn w EMMA Jan. 23, 1958 E KRAUSE 3,364,703

CONTROL MECHANISM FOR THE YARN CARRIER STOPS OF A FLAT KNITTING MACHINE Fi led March 17, 1965 5 Sheets-Sheet 4 Jan. 23, 1968 E. KRAUSE 3,364,703 CONTROL MECHANISM FOR THE YARN CARRIER STOPS OF A FLAT KNITTING MACHINE Filed March 17, 1965 5 Shets-Sheet 5 .l I g l NVE N TO R Erich Krausa United States Patent 3,364,703 CONTROL MECHANISM FOR THE YARN CARRIER STOPS OF A FLAT KNITTING MACHINE Erich Krause, Bopfingen, Germany, assignor to Universal Maschinenfabrik Dr. Rudolf Schieber G.m.b.H., Westhausen, Wurttemberg, Germany Filed -Mar. 17, 1965, Ser. No. 440,355 Claims priority, application Germany, Mar. 18, 1964, U 10,592 4 Claims. (Cl. 66-126) ABSTRACT OF THE DISCLOSURE The right and left yarn carrier stops of a flat knitting machine are coupled in pairs by racks and pinions so that they move symmetrically inward and outward when a connected slide is moved by a reversible electrical motor through a transmission which includes a threaded spindle engaging the slide. The motor is controlled through relays by two switches adapted to be operated by punched cards and by a limit switch operated by one of the stops.

This invention relates to flat knitting machines, and particularly to a mechanism for automatically controlling the positions of the yarn carrier stops, and for thereby varying the width of the fabric which is being knitted.

Known devices which vary the width of a knitted fabric by shifting the yarn carrier stops are relatively complex. They are not only costly to build, but occupy much space that cannot readily be spared. They are also limited in the range of movements that can be imparted to the yarn carrier stops: While the stops may be moved in one direction in increments corresponding to the width of a single needle, the return movement must always terminate in a single fixed position.

The object of the invention is the provision of a con trol mechanism for the yarn carrier stops of a fiat knitting machine which is free from the shortcomings and limitations of the aforedescribed known apparatus.

A more specific object is the provision of a control mechanism which permits the yarn carrier stops to be moved automatically in both directions in increments corresponding to the width of a single needle space, but also permits automatic return movement in one or more steps of adjustable length greater than a single needle space.

With these and other objects in view, the invention provides a prime mover which is connected to the yarn carriers for moving the same on the supporting frame of the knitting machine, and a program source connected to the prime mover for energizing the same according to the program of the source, the prime mover being separate and independent from the main drive of the knitting machine.

Typically, the prime mover is a reversible electric motor, and the program source is the usual punched card system of the knitting machine which operates switches in circuit with the motor. The switches provide only a brief energizing signal, and a holding circuit is provided to keep the motor energized for a predetermined period after starting. Arresting means prevent further movement of the control mechanism after deenergizing of the motor at the end of the predetermined period.

Other features and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description of a preferred embodiment when considered in connection with the accompanying drawings in which:

FIG. 1 shows a flat knitting machine of the invention in fragmentary front elevation;

FIG. 2 shows the apparatus of FIG. 1 in plan view;

FIG. 3 shows a detail of the apparatus of FIG. 1 in side elevational section on a larger scale;

FIG. 3A is a front elevational view of the device of FIG. 3;

FIG. 3B shows the device of FIG. 3 in plan view;

FIG. 4 is another front elevational detail view, partly in section, on the line IV-IV of the knitting machine of FIG. 2;

FIG. 5 shows another detail of the knitting machine, located below the device of FIG. 4, in a View analogous to that of FIG. 4; and

FIG. 6 is a wiring diagram of the apparatus of FIGS. 1 to 5.

Referring now to the drawing in detail, and initially to FIGS. 1 and 2, there are seen the front yarn carrier bar 296 and the rear yarn carrier bar 295 of a flat knit ting machine which may be entirely conventional as far as not shown and described herein.

Movements of yarn carrier boxes, not themselves shown in the drawing, on the bars 295, 296 are limited by stops whose elongated supporting blocks 293, 294-, 297, 298 are slidably mounted near the ends of the bars 295, 296. Pairs of stopping noses 2-99, 300, 301, 302 are arranged respectively on the blocks, and the members of each pair are staggered in such a manner as to limit movement of the yarn carrier in the desired manner.

Guide members 303, 304, 311, 312 are slidably supported on the bars 295, 296 near respective supporting blocks and are equipped with racks, the racks 305, 306 of the guide members 303, 304 being shown in FIG. 1. The racks 305, 306 are coupled to associated racks 309, 310 by pinions 307, 308 which are mounted on the bar 295 for rotation about fixed axes. The racks 309, 310 are respectively fixedly fastened on the blocks 293, 294. When the blocks 293, 294, 297, 298 move outwardly or away from each other, the associated guide members 303, 304, 311, 312 move inwardly or toward each other, and vice versa.

Pull rods 333, 314, 315, and 316 connect the guide members and blocks associated with the same yarn carrier bar. Referring specifically to FIG. 1, the left end of the pull rod 313 is attached to the block 293, and its right end to the guide member 3'04. The left end of the pull rod 314 is connected to the guide member 303, and the right end to the block 294. The rods are therefore stressed in tension onlv under all operating conditions.

The yarn carrier stops are attached to the pull rods in a manner shown on a larger scale in FIGS. 3, 3A, and 3B with respect to one pair of stops. Bores 32.5, 326 in the stops are aligned transversely of the direction of elongation of the bars 295, 296 and respectively receive the head 323 of a clamping screw 321 and an internally threaded bushing 324 which is engaged by the screw 321. The screw 321 passes through openings in the two clamping arms of a clamp 322 which is provided with two passages at right angles to the axis of the screw 321. When the screw 321 is tightened, as shown in FIG. 3, the pull rod 313 is fixedly fastened to the clamp 322 in one of the passages, and is locked to the carrier stops by the screw 321 and the bushing 324 so that the stops move with the rod 313 on the bar 295. The other passage 327 is oversized so as to permit free movement of the pull rod 31-; which is received therein.

The carrier stops may thus be set on the associated pull rods to the desired initial width of the knitted fabric and move inwardly and outwardly together with the supporting blocks under the control of a mechanism shown in detail in FIGS. 4 to 6, and only partly represented in FIGS. 1 to 3 by a slide 328.

As better seen in FIG. 4, the slide 323 is guided longitudinally of the bars 295, 296, not themselves visible in FIG. 4, by rails 329, 330 which are elements of the stationary supporting frame of the knitting machine, the machine being shown only to the extent necessary for an understanding of this invention. Forked integral lugs 331, 332 on the slide 328 engage the guide members 304 and 312, as is best seen in FIG. 2, and thereby connect the several guide members and carrier stops for joint movement. The slide 328 permits each yarn carrier bar to be removed individually from the knitting machine, and to be disengaged from the stop control mechanism without the use of tools.

The longitudinal movement of the slide 328 is controlled by a partly threaded spindle 333 which engages an internally threaded block 334 on the underside of the slide 328 between the two bars 295, 296. Smooth journals on the spindle 333 are axially secured in bearings 335, 336 on the machine frame. A bevel gear 338 on one end of the spindle 333 meshes with an identical bevel gear 339 on the upper end of an upright shaft 340.

The lower end of the shaft 340 and associated drive elements are shown in FIG. 5. An electric motor 341 drives the shaft 340 by means of a spur gear 342 on the output shaft of the motor and a pinion 343 keyed to the shaft 340.

The lower end of the shaft 340 also carries a disc 345 having two diametrically opposed V-notches, better seen in FIG. 6. In the position of the device illustrated in FIG. 5, one of the notches is engaged by a click 356 under the urging of a tension spring 357. The click 356 is mounted on the machine frame for sliding movement in a direction radial to the axis of the shaft 340 and carries a projection 358 for actuating two microswitches 347, 348, also mounted on the frame, when the click 356 moves radially outward of a notch in the disc 345. The strength of the spring 357 is selected in such a manner in relation to the inclination of the cam faces in the V- notches of the disc 345 that the click moves outward of an engaged V-notch when the motor 341 is energized, but is retained in a notch against the inertia of the moving elements coupled with the shaft 340 when the motor 341 is deenergized.

The electrical control circuit of the motor 341 is diagrammatically illustrated in FIG. 6. The disc 345 and the click 356 are shown twice in the diagram for clearer illustration of their cooperation with the microswitches 347, 348.

The power supply of the circuit is a three-phase alternating current four-wire system R, S, T, Mp. Its operation is controlled by a system of moving punched cards, conventional in itself, and not shown in the drawing, which closes normally open switches 400, 401 in timed sequence. The switch 400 is arranged parallel to the normally open microswitch 347 and in series circuit with a normally closed set of contacts in the switch 467 of a relay 403 and the coil of a relay 402.

The switch 401 is arranged parallel to the normally open microswitch 348 and in series circuit with a normally closed set of contacts of the relay 402 and the coil of the relay 403. The relay 402, when energized, closes a normally open power switch 404 in the energizing circuit of the motor 341 to cause forward rotation of the spur gear 342 and movement of the yarn carrier stops. A similar power switch 405 of the relay 403 is connected to the motor 341 to cause backward rotation thereof when the relay 403 is energized. A normally applied spring-and-solenoid operated brake 406 is connected to the swiches 404, 405 in such a manner that the brake 406 is released by its solenoid when either switch 404, 405 is closed.

The punched perforations in the non-illustrated moving cards are sensed by actuating members of the switches 400, 401 in the usual manner. When the switch 400 is riefly closed by passage of a perforation over the associated sensing or actuating member, the relay 402 attracts its armature, interrupts the energizing circuit of the relay 403, and closes the power switch 404. As the motor starts rotating, the click 356 is expelled from the V-notch in which it was originally received, and the microswitches 347, 348 are closed. Ciosing of the microswitch 348 has no effect because its circuit is interrupted at the relay 202. The closed microswitch 347 keeps the motor 341 energized after the switch 400 has been opened, until the disc 345 has completed one half of a revolution, and the click 356 has dropped into the other V- notch of the disc, thereby interupting the energizing circuit of the relay 402, opening the power switch 404, applying the brake 406, and arresting any inertial movement of the shaft 340 and of the devices coupled therewith for joint movement.

The pitch of the threaded spindle 333 is selected in such a manner than one half of a spindle revolution changes the fabric width by one needle at gages 10 to 14. For knitting gages 4 to 8, the disc 345 is replaced by another, non-illustrated disc having only one notch so that the spindle 333 makes a full turn in response to each perforation on the control card, and the carrier stops move correspondingly in a manner obvious from the preceding description of the stop arrangement. recise positioning of the stops is achieved by the cooperation of the click 356 with the disc 345.

The return movement of the carrier stops is controlled by actuation of the switch 401 by the punched cards in a manner closely similar to the afore-described narrowing movement of the stops by the switch 400. Closing of the switch 401 energizes the relay 403, thereby interrupting the energizing circuit of the relay 402 at the switch 407. The last mentioned switch closes a holding circuit through a normally closed limit switch 408 arranged on the stationary structure of the knitting machine, as shown in FIG. 1.

The relay 403 attracts its armature, thereby energizing the motor 341 for backward rotation of the gear 342, and simultaneously releasing the brake 406. The motor rotates until a earn 409 engages and opens the limit switch 408. The cam is mounted on the block 294 shown in FIG. 1, but numerous other arrangements are obviously possible.

More than one limit switch 408 may be provided on the block 294 if return of the yarn carrier stops to their initial position in several steps is desired, and two cams are illustrated in FIG. 6. It will be understood that they are releasably fastened to the supporting block and are spaced in the direction of block movement. Their positions are adjustable in the last-mentioned direction, and such adjustment need not be made with extreme preci sion. Backward rotation of the motor 341 continues after opening of the limit switch 408 until the click 356 drops into the next notch of the disc 345, thereby ensuring precise positioning of the yarn carrier stops relative to the non-illustrated needle beds of the knitting machine.

If it is desired to shift the yarn carrier stop in both directions in single-needle steps, the limit switch 408 is opened manually, and held in the open position in any desired manner.

Various other modifications are contemplated and may he obviously resorted to by those skilled in the art with out departing from the spirit and scope of the invention as hereinafter defined by the appended claims, as only a preferred embodiment thereof has been disclosed.

What is claimed is:

1. In a control mechanism for a knitting machine. in combination:

(a) a support;

(b) a yarn carrier stop movable on said support;

(c) a reversible electric motor;

(d) a program source including a switch adapted to be gizing connection between said source of electric current actuated by a punched card; and said electric motor for a predetermined period after (e) a source of electric current; said energizing thereof.

(f) connecting means operatively connecting said 3. In a mechanism as set forth in claim 2, arresting sources to said motor for energizing said motor in 5 means for arresting said movement of said yarn carrier response to the program of said program source; stop at the end of said predetermined period. and 4. In a mechanism as set forth in claim 2, said holding (g) motion transmitting means operatively interposed circuit means including limit switch means having a between said motor and said yarn carrier stop for switch member and a switch actuating member, one movement of said stop by said motor, 10 member of said limit switch means being mounted on said (1) said connecting means including a peripheralsupport and the other member of said limit switch means ly notched disc member having an axis and conbeing connected to said yarn carrier stop for joint movenected to said motor for rotation about said axis ment therewith, said limit switch means being adapted when said motor is energized, a click member to open said holding circuit means in response to a preradially movable toward and away from said determined movement of said yarn carrier stop on said disc member, yieldably resilient means urging support. said click member toward the periphery of said References Cited disc member and inward of a notch thereof, UNITED STATES PATENTS and holding circuit means for connecting said motor to said source of electric current, said 2625025 1/1953 Zesch 66 149 holding circuit means including a normally open 3019626 2/1962 Blood 66*39 switch and actuating means connecting said x s et 66*154 switch to sald click member for closing said 3,262,286 7/1966 Bentley et a1. 66 89 switch when said click member is outside said notch. 2, In a mechanism as set forth in claim 1, said holding MERVIN STEIN Primary Examiner circuit means including means for maintaining an ener- FELDBAUM, Assistant Examiner- 

